Download or read book Measurement of D 0 bar D 0 Mixing From a Time Dependent Amplitude Analysis of D 0 K pi pi0 Decays written by and published by . This book was released on 2008 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of D0 bar D 0 Mixing With a Time Dependent Amplitude Analysis of D0 2 K pi pi 0 written by and published by . This book was released on 2013 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flavor mixing of neutral mesons is a long and well known phenomenon in particle physics. Experimental evidence of mixing of the neutral kaon was obtained in 1956, followed in 1987 by the evidence of Bd mixing. In 1974, A. Pais and S.B. Treiman firstly introduced the idea of charm mixing and CP violation. Even though many searches were conducted over time, it was clear that the small scale at which both amplitude and frequency of the oscillation took place made any possible observation challenging. In 2007, both the BABAR and Belle experiments announced the first evidence of mixing in the charm sector. The analyses concerned the study of a two body decay of the D0 meson. Few months later, BABAR presented the analysis of the decay D0 2!K+[pi]-[pi]0 . This is the main topic of this thesis.

Download or read book Measurement of D0 bar D 0 Mixing With a Time Dependent Amplitude Analysis of D0 u2192 K 0 written by and published by . This book was released on 2013 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flavor mixing of neutral mesons is a long and well known phenomenon in particle physics. Experimental evidence of mixing of the neutral kaon was obtained in 1956, followed in 1987 by the evidence of Bd mixing. In 1974, A. Pais and S. B. Treiman firstly introduced the idea of charm mixing and CP violation. Even though many searches were conducted over time, it was clear that the small scale at which both amplitude and frequency of the oscillation took place made any possible observation challenging. In 2007, both the BABAR and Belle experiments announced the first evidence of mixing in the charm sector. The analyses concerned the study of a two body decay of the D0 meson. Few months later, BABAR presented the analysis of the decay D0 → K+?-?0 . This is the main topic of this thesis.

Download or read book Study of D0 D 0 Mixing Parameters Using a Time Dependent Amplitude Analysis of the Decay D0 K0S pi pi written by Rolf Andreassen and published by . This book was released on 2010 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: I present a measurement of the mixing parameters in the D meson system, using 473.5 inverse fb of data from the BaBar detector. A time-dependent fit to the Dalitz plot of the decay D^0 -> K_S pi+ pi-, assuming no CP violation, finds for the DDbar mixing parameters, the normalised mass and width differences x and y, x = (0.43 ± 0.25 ± 0.20)% y = (0.70 ± 0.22 ± 0.17)% where the uncertainties are statistical and systematic. For D and Dbar samples separately, we find x(D) = (0.49 ± 0.36 ± 0.20)% y(D) = (0.82 ± 0.31 ± 0.17)% x(Dbar) = (0.46 ± 0.35 ± 0.20)% y(Dbar) = (0.55 ± 0.31 ± 0.17)%.

Download or read book Analysis of D0 K Pi Pi0 Decays written by Michael Galante Wilson and published by . This book was released on 2005 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analyzing D{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} decays, herein are presented the methods and results of a search for D{sup 0}-{bar D}{sup 0} mixing, a measurement of the branching ratio R {equivalent_to} {Lambda}(D{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0})/{Lambda}(D{sup 0} {yields} K{sup -}{pi}{sup +}{pi}{sup 0}), and measurements of the contributions from D{sup 0} {yields} K{sup +}{rho}{sup -}, K*{sup +}{pi}{sup -}, K*{sup 0}{pi}{sup 0}; 230.4 fb{sup -1} of data collected from the BABAR detector at the PEP-II collider during 2000-2004 (Runs 1-4) are analyzed. An event-level tagging technique is developed, which facilitates the accurate determination of doubly Cabibbo-suppressed resonance contributions by suppressing background from Cabibbo-favored decays. The branching ratio is measured as R = (0.214 {+-} 0.008 (stat) {+-} 0.008 (syst))%, with (46.1 {+-} 3.3 (stat) {+-} 2.9 (syst))% of D{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} decays proceeding through the channel D{sup 0} {yields} K*{sup +}{pi}{sup -}. The data are consistent with the null-D-mixing hypothesis at a confidence level of 10%, and the expected value of {+-} {radical}(x{sup 2} + y{sup 2}) is measured as -0.013 {+-} 0.010 (stat), indicating negative interference between mixing and doubly Cabibbo-suppressed decay. The expected value of the integrated mixing rate is (x{sup 2} + y{sup 2})/2 = (0.013 {+-} 0.013 (stat))%.

Download or read book Analysis of D 0 bar D 0 Mixing in D 0 K pi Decays Using the CDF II Detector written by and published by . This book was released on 2009 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: We presented the first observation of D0-$\bar{D}$0 mixing in a single analysis. We measured the ratio of doubly Cabibbo suppressed or WS (D0 → K+[pi]-) decay rate to Cabibbo favored or RS (D0 → K-[pi]+) decay rate as a function of D0 decay time. We used an integrated luminosity of 4.0 fb-1 of proton anti-proton collisions at √s = 1.96 TeV at the collider detector at Fermilab (CDF II).

Download or read book Search for D sup 0 bar D sup 0 Mixing and a Measurement of the Doubly Cabibbo suppressed Decay Rate in D sup 0 yields K pi Decays written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results of a search for D[sup 0]-[bar D][sup 0] mixing and a measurement of R[sub D], the ratio of doubly Cabibbo-suppressed decays to Cabibbo-favored decays, based on an analysis of D[sup 0][yields] K[sup+][pi][sup -] decays in 57.1 fb[sup -1] of data collected at or just below the[Upsilon](4S) resonance with the BABAR detector at the PEP-II collider. Our results are compatible with no mixing and no CP violation. At the 95% confidence level, allowing for CP violation, we find the mixing parameters x[prime][sup 2]

Download or read book Measurement of D0 D0bar Mixing Using the Ratio of D0 K pi and K K Lifetimes written by and published by . This book was released on 2009 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We measure the rate of D°-{bar D}° mixing with the observable y{sub CP} = (?{sub K?}/?{sub KK}) - 1, where?{sub KK} and?{sub K?} are respectively the mean lifetimes of CP-even D° → KK− and CP-mixed D° → K−?+ decays, using a data sample of 384 fb−1 collected by the BABAR detector at the SLAC PEP-II asymmetric-energy B Factory. From a sample of D° and {bar D}° decays where the initial flavor of the decaying meson is not determined, we obtain y{sub CP} = [1.12 ± 0.26(stat) ± 0.22(syst)]%, which excludes the no-mixing hypothesis at 3.3?, including both statistical and systematic uncertainties. This result is in good agreement with a previous BABAR measurement of y{sub CP} obtained from a sample of D*+ → D°?+ events, where the D° decays to K−?+, K+K−, and {pi}+{pi}−, which is disjoint with the untagged D° events used here. Combining the two results taking into account statistical and systematic uncertainties, where the systematic uncertainties are assumed to be 100% correlated, we find y{sub CP} = [1.16 ± 0.22(stat) ± 0.18(syst)]%, which excludes the no-mixing hypothesis at 4.1?

Download or read book Amplitude Analysis of the Decay D0 to K K pi0 written by and published by . This book was released on 2007 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using 385 fb−1 of ee− collisions, they study the amplitudes of the singly Cabibbo-suppressed decay D° → K−K+?°. They measure the strong phase difference between the {bar D}° and D° decays to K*(892)+K− to be -35.5{sup o} ± 1.9{sup o}(stat) ± 2.2{sup o}(syst), and their amplitude ratio to be 0.599 ± 0.013(stat) ± 0.011(syst). They observe contributions from the K? and K−K+ scalar and vector amplitudes, and analyze their angular moments. They find no evidence for charged?, nor for higher spin states. They also perform a partial wave analysis of the K−K+ system in a limited mass range.

Download or read book Measurement of the Ratio of Decay Amplitudes for B0bar J psi K 0 and B0 J psi K 0 written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have measured the time-dependent decay rate for the process B [yields] J/[psi] K*[sup 0](892) in a sample of about 88 million [Upsilon](4S) [yields] B[bar B] decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. In this sample we study flavor-tagged events in which one neutral B meson is reconstructed in the J/[psi]K*[sup 0] or J/[psi] [bar K]*[sup 0] final state. We measure the coefficients of the cosine and sine terms in the time-dependent asymmetries for J/[psi]K*[sup 0] and J/[psi][bar K]*[sup 0], find them to be consistent with the Standard Model expectations, and set upper limits at 90% C.L. on the decay amplitude ratios A([bar B][sup 0] [yields] J/[psi]K*[sup 0])/A(B[sup 0] [yields] J/[psi]K*[sup 0])

Download or read book Search for D0 Anti D0 Mixing and Branching Ratio Measurement in the Decay D0 to K Pi Pi0 written by and published by . This book was released on 2006 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a search for D°-{bar D}° mixing using regions of phase space in which the rate of doubly Cabibbo-suppressed decays D° → K+?−?° relative to Cabibbo-favored decays D° → K− ?+?° is reduced. They analyze 230.4 fb−1 of data collected with the BABAR detector at the PEP-II e+e− collider at SLAC. They present results with and without the assumption of CP conservation. Assuming CP conservation, they measure the time-integrated mixing rate R{sub M} = (0.023{sub -0.014}{sup +0.018}(stat.) ± 0.004(syst.))%, and R{sub M}

Download or read book Search for D sup 0 bar D sup 0 Mixing Using Semileptonic Decay Modes written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on an 87-fb[sup -1] dataset collected by the BABAR detector at the PEP-II asymmetric-energy B-Factory, a search for D[sup 0]-[bar D][sup 0] mixing has been made using the semileptonic decay modes D*[sup +] --> [pi][sup +] D[sup 0][sub z] D[sup 0] --> K*[epsilon][nu] (+c.c.). The use of these modes allows unambiguous flavor tagging and a combined fit of the D[sup 0] decay time and D*[sup +]-D[sup 0] mass difference ([Delta]M) distributions. The high-statistics sample of unmixed semileptonic D[sup 0] decays is used to model the [Delta]M distribution and time-dependence of mixed events directly from the data. Neural networks are used to select events and reconstruct the D[sup 0]. A result consistent with no charm mixing has been obtained. R[sub mix] = 0.0023 [+-] 0.0012 [+-] 0.0004. This corresponds to an upper limit of R[sub mix]

Download or read book D sup 0 Mixing Lifetime Differences and Hadronic Decays of Charmed Hadrons written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented are preliminary results from the BABAR Collaboration on charm physics, including limits on D[sup 0] mixing from the ratio of lifetimes from K[sup -][pi][sup+], K[sup+]K[sup -], and[pi][sup+][pi][sup -] final states (using 47.8 fb[sup -1] of data) and branching ratio, and Dalitz amplitude analyses of the decays D[sup 0][yields] K[sup 0]K[sup -][pi][sup+], [bar K][sup 0]K[sup+][pi][sup -], and[bar K][sup 0]K[sup+]K[sup -] (using 22 fb[sup -1] of data). The status of direct measurements of D[sup 0] mixing using wrong-sign D[sup 0][yields] K[sup+][pi][sup -] decays is also discussed.

Download or read book Determination of the Wrong Sign Decay Rate D0 K pi and the Sensitivity to D0 D0bar Mixing written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The D[sup 0] meson can decay to the wrong sign K[sup+][pi][sup -] state either through a doubly Cabibbo suppressed decay or via mixing to the[bar D][sup 0] state followed by the Cabibbo favoured decay[bar D][sup 0][yields] K[sup+][pi][sup -]. We measure the rate of wrong sign decays relative to the Cabibbo favoured decay to (0.383[+-] 0.044[+-] 0.022)% and give our sensitivity to a mixing signal.

Download or read book Time Dependent Dalitz Analysis of B0 D K0 Pi Decays for the Measurement of 2beta gamma with the BaBar Detector written by Francesco Polci and published by . This book was released on 2007 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The CP violation is explained in the Standard Model with three quark generations with an irreducible phase in the Cabibbo-Kobayashi-Maskawa quark mixing matrix. The unitarity of this matrix can be represented in a complex plane as a triangle (called Unitarity Triangle). The measurement of the parameters of the triangle is a powerful test of the Standard Model description of the CP violation. This thesis tries to measure the weak phase 2beta+ gamma through the B0 -> D+ K0 Pi- decays. Respect to the two body decays B0 -> D(*)+ Pi- and B0 -> D+ Rho- presently used for the measurement of the same weak phase, the B0 -> D+ K0 Pi- decays should show up a larger CP asymmetry and does not rely on any theoretical assumption. After a review of all the methods for the measurement of 2beta+gamma, the thesis presents the results of a feasibility study of the measurement with the B0 -> D+ K0 Pi- decays . In a second part, the analysis performed on 316 fb-1 of data collected by the BaBar detector at the B-factory PEP2 is presented, from the selection of the events to the time-dependent Dalitz fit technique used in order to extract the weak phase 2beta+gamma as well as the amplitudes and phases of the intermediate resonances contributing to the decay. The result of the analysis gives the following estimation: 2beta+gamma = 89 +/- 53(stat) +23-14(syst) degrees with an irreducible ambiguity of 180 degrees.

Download or read book Search for D0 D 0 Mixing in D0 K pi pi pi Decays written by Yi Zheng (Ph. D.) and published by . This book was released on 2008 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results of a search for D0-D̄0 mixing by analyzing D0 --> K [pi]− [pi]− [pi]+ decays from events in 230.4 fb-1 e+e- data recorded by BABAR. Assuming CP conservation, we measure the time-integrated mixing rate RM = (0.0019 ... (stat.) ± 0.002 (syst.))%, and RM

Download or read book PRELIMINARY STUDY OF D0 K PI PI0 DECAYS WITH DALITZ PLOTS written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle physicists study the smallest particles and most basic rules of their interactions in humankind's current scope. The Charm Analysis Working Group (CWG) of the BaBar Collaboration studies decays involving the charm quark. They currently study mixing in D decays, an interesting and poorly understood phenomenon in current physics models. We, as part of the CWG, investigated the plausibility of using Dalitz plots and the BaBar analysis framework to study mixing in Wrong Sign (WS) D[sup 0][yields] K[pi][pi][sup 0] decays. Others in the CWG have studied mixing in the 2-body decay, D[sup 0][yields] K[pi]. The 3-body decay analyzed with the RooFitDalitz analysis package and Dalitz plots provides more information and another way of separating Doubly Cabibbo Suppressed Decays (DCSD) from mixing--which share the same end products. Through doing many simulations, we have demonstrated the usefulness of this approach. We selected D[sup 0][yields] K[pi][pi][sup 0] events from Simulation Production run No. 4 (SP4) and BaBar's run 1 and run 2. We made Dalitz plots with this data. Now that we better understand Dalitz plots and software, we plan to select WS D[sup 0][yields] K[pi][pi][sup 0] events and perform rate fits as discussed in BaBar Analysis Document (BAD) No. 443, as well as fits for several different decay times and resonances, in order to further distinguish DCSD from mixing.